An array substrate is one of core components in a liquid crystal display panel, and the array substrate comprises: a plurality of data lines and a plurality of gate lines. A mother board of liquid crystal display panel which is large-sized is formed by ceiling a mother board of array substrate having a plurality of array substrates and a mother board of color filter substrate having a plurality of color filter substrates (or a mother board of array substrate and a mother board of cover plate). A cutting process on the mother board of liquid crystal display panel is preformed to form single panels which are applied to various display products. After the cutting process, it is necessary to perform a cell test on each of the single panels to determine the quality thereof.
Since signal lines (such as the data lines and the gate lines) are prone to break during the preparation process of the liquid crystal display panel, and the data lines and the gate lines cannot normally transmit signals after they are broken, the conformity rate of the liquid crystal display panel is reduced. Under this circumstance, it is necessary to detect and repair the broken lines of the signal lines on the array substrate in the liquid crystal display panel to improve the conformity rate thereof.